Centrifugal pump



June 3, BL

CENTRIF'UGAL PUMP Filed Jan. 9, 1967 lld INVENTOP ALBE RT BLUM wg United States Patent .0

3,447,475 CENTRIFUGAL PUMP Albert Blum, Scheiderhohe, Siegkreis, Bezirk Cologne, Germany Filed Jan. 9, 1967, Ser. No. 607,927 Int. Cl. F04d 29/00, 1/04 US. Cl. 103-111 1 Claim BACKGROUND OF THE INVENTION Field of the invention The instant invention provides a device consisting essentially of a generally circular housing having a central inlet and an tangential outlet with the walls of the outlet merging smoothly with the walls of the housing. Internally is provided an impeller having its blades extending toward one housing end wall and spaced radially inward from the peripheral wall of the housing, while the housing end wall facing the vanes or blades is provided with arcuate ribs for guiding solid matter radially outward for discharge from the housing.

Description of the prior art As is well known to those versed in the art, centrifugal pumps are particularly useful in pumping of dirty liquids, such as waste Waters containing solid components of various kinds. In the event of solids, such a flexible sheet materials being sucked into conventional centrifugal pumps, there is great likelihood of clogging as at the pump inlet, in the pump housing, between the housing and impeller, or by winding about the impeller or shaft. Such clogging may completely disable the pump, often causing damage and requiring immediate attention.

SUMMARY Accordingly, it is an important object of the present invention to provide a highly improved construction of centrifugal pump for use in pumping dirty liquids, say submerged in a sump, or otherwise, wherein flexible sheet materials, such as textiles, are adapated to be readily passed through the pump, for movement with the pumped liquid, without clogging or damage to the pump.

It is still a further object of the present invention to provide a unique and highly improved pump construction of the type described wherein guide means are provided for guiding flexible sheet materials and other solids from the pump inlet radially outward within the housing to a clear annular chamber for movement therefrom through the pump outlet or discharge.

It is still another object of the present invention to provide a centrifugal pump construction having the advantageous characteristics mentioned in the preceding paragraphs, wherein projections likely to snag flexible sheet materials in the pump construction for cutting action against flexible sheet material being pumped to effect size reduction and facilitate the pumping of such materials.

It is a further object of the present invention to provide a centrifugal pump construction having the unique advantages and structural features mentioned in the preceding paragraphs, which is extremely simple in structure, durable and reliable throughout a long useful life, and which can be economically manufactured for sale at a reasonable price.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claim.

DESCRIPTION OF DRAWINGS In the drawings:

FIGURE 1 is a sectional view taken generally along the line 11 of FIGURE 2, showing a centrifugal pump constructed in accordance with the teachings of the present invention; and

FIGURE 2 is a horizontal cross-sectional view taken generally along the line 22 of FIGURE 1.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now more particularly to the drawings, a housing is there generally designated 11, and may include generally circular upper and lower end walls 11a and l lb disposed in parallel spaced facing relation. Extending between the pe-riperal edges of the end walls 11a and 11b, and there about is a peripheral or side wall 11c. Formed centrally through the upper end Wall 11a is an opening 11d, for a purpose appearing presently. An inlet opening He is formed centrally through the lower end wall 11b for receiving material to be pumped. At one location of the pheripheral wall 11c, there is formed therein a discharge opening 11 Anoutlet conduit 12 is rigidly connected or formed integral with the upper and lower housing end walls 11a and 11b, and the housing peripheral wall 110, and communicates through the discharge opening 11 with the interior of the housing 11. The discharge conduit 12 extends generally tangentially of the generally circular housing 11 and has its outer side 12c smoothly merging with the adjacent portion of peripheral wall in tangential relation, while its inner side 12d merges smoothly in an arcuate configuration, as at 23, with the peripheral wall portion adjacent thereto. Thus, as best seen in- FIGURE 2, the interior of the housing 11 opens smoothly into and through the outlet conduit 12 with a complete absence of internal projections or obstructions. In particular, the arcuate wall portion 23 merges smoothly with the side 12d of conduit 12 and the peripheral wall 11c of housing 11.

The lower end wall 11b includes an outer portion 19 extending inward from the peripheral wall 110, and an annular central portion 21 either fixedly secured by any suitable means in snug fitting relation within the outer portion 19 or formed integral therewith. The central portion 21 is formed on its upper surface, interiorly of the housing 11 with a series of upstanding ribs 22 extending spirally from the central opening 20 of the central portion 21 to the outer edge thereof, terminating at the outer portion 19, spaced inward from the peripheral wall 110. Thus, the central lower end wall section 21 is of generally circular-outline configuration, and the ribs 22 extend spirally to the circular outer extremity of the section 21. The ribs 22 upstand at an elevation above that of the adjacent outer lower end wall portion 19 and may have relatively sharp upper edges.

Secured centrally within the central aperture 20 of section 21, as by fasteners 22a, is an annular fitting 24 provided on its upper surface, internally of the housing 11, with an annular, upstanding cutting edge 25. As best seen in FIGURE 2, the cutting edge 25 is of undulate configuration, extending a'bout the fitting 24 in an undula-te relation therealong.

Interiorily of the housing 11, adjacent to the upper end wall 11a is a generally flat, substantially circular impeller plate 13. The plate 13 may be provided with a boss or hub 13a upstanding from the plate through the upper end wall opening 11d, for connection to a drive shaft 17. The plate 13 may be of a diameter substantially equal to that of the lower end wall section 21, and spaced over the latter.

Depending from the under or inner side of the impeller plate 13 are a pair of impeller vanes 14 and 15. The vanes 14 and 15 may be substantially identical, projecting downward from the plate 13 and terminating at their lower edges proximate to the upper edges of ribs 22. Further, the vanes 14 and 15 may extend in a spiral configuration about the axis of housing 11 from a radially inner point substantially directly over the cutting edge 25 to a radially outer point at the periphery of plate 13. In addition, the blades or vanes 14 and 15 may taper or reduce in thickness between their radially inner and outer ends, and the leading edges may extend obliquely downwardly and radially outward, as at 141 and 151, respectively. More specifically, the leading edges 141 and 151 of respective vanes 14 and 15 may depend in a radially outwardly inclined relation, with their lower extremities just outward of the undulate cutting edge 25.

In operation, the shaft 17 is driven by a motor or other suitable drive means, to rotate the impeller plate 13 and blades 14 and 15 within the confines indicated by the dot-and-dash outline in FIGURE 1. It will thus be appreciated that radially outward of the impeller blades 14 and 15 is a clear, generally annular passageway 16 free of obstruction and of a substantially constant radial dimension which opens into the outlet conduit 12.

Impeller rotation efr'ects upward suction or withdrawal through the central lower end wall opening 112 of fitting 20, from which the material being pumped is impelled outwardly by the impeller blades 14 and 15. Solid matter, such as flexible sheet material, say textiles or rags may be impelled free of the impeller into the annular chamber 16 for exit through the outlet conduit 12. The inclined leading vane edges 141 and 151 cannot catch on such solid material, but should the solid material engage between the vanes and undulate cutting edge 25, there is a cutting action to sever and weaken the material, the cutting action being enhanced by the undulant configuration of edge 25 without requirement of appreciable power increase. Further, the ribs 22, by their sharp edges also serve to abrade, sever and weaken such solid material, and the grooves between the ribs 22 efiectively guide the solid material radially outward to the outer annular passageway 16. The inclined leading vane edges 141 and 151 also facilitate movement of solid material toward the ribs 22 to be guided by the latter into passageway 16.

From the foregoing, it is seen that the present invention provides a centrifugal pump construction which fully accomplishes its intended objects and is well adapted to meet practical conditions of manufacture, installation, maintenance and use.

Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be made within the spirit of the invention and scope of the appended claim.

What is claimed is:

1. A centrifugal waste water pump comprising a hollow housing, said housing having a pair of generally circular facing end walls joined by a smooth continuous peripheral wall extending about said end walls, the opposite ends of said peripheral wall defining with said end walls an outlet opening from the housing, one of said end walls having a central inlet, an impeller in said hollow housing, said impeller having a plate adjacent said other end wall, at least a pair of impeller vanes extending from said plate toward said one end wall, said vanes having leading edges spaced from the axis of rotation of said impeller and extending obliquely from said plate, said vanes having concave inner surfaces and covex outer surfaces and sharp trailing edges, said leading edges of said impeller being relatively blunt with respect to said sharp trailing edges, said vanes being curved rearwardly from the leading edges to the trailing edges thereof in a direction opposite to the direction of rotation of the impeller, the trailing edges of said vanes terminating short of the peripheral wall of said housing, said one end wall having a plurality of closely spaced internal ribs circumferentially spaced about said inlet, said ribs having outer ends spaced inwardly of said peripheral wall of the housing and curving oppositely from said impeller vanes, whereby an unrestricted annular chamber is formed be tween the said ribs and vanes and the internal surface of said peripheral wall, a cutting ring circomposed about said inlet opening, said ring including an axially directed cutting edge of undulate configuration extending inwardly of the housing, the wave crests of said undulating configuration projecting towards and closely adjacent the leading edges of said vanes, said vanes terminating in free end faces closely adjacent said ribs whereby any sheet meterial in the waste water is subject to cutting action by the vanes while passing between said vanes and the cutting ring and between said free end faces of said vanes and said ribs to pass through said unrestricted annular chamber about said impeller and outer said discharge opening.

References Cited UNITED STATES PATENTS 1,182,439 5/1916 Wood. 1,763,595 6/ 1930 Paatsch 103-1l4 2,245,035 6/ 1941 Hartman 103-111.1 2,371,681 3/1945 Durdin 10311l.1

FOREIGN PATENTS 538,150 3/ 1955 Belgium. 577,051 5 1924 France. 1,377,185 9/ 1964 France.

274,809 1/ 1914 Germany.

HENRY F. RADUAZO, Primary Examiner.

U.S. Cl. X.R. 103103 

